Hello everyone, I have browsed around this site for years and finally joined.

Recently my 98 Ram 5.9 died on me. It had a dead battery however when I jump started the vehicle on my high amp charger the main battery terminal sparked and there was a constant clicking sound from inside the cab. After that, I purchased a new battery however now i have no spark and no fuel.

I have bypassed the fuel relay and the pump does still work and there is solid pressure at rail. It does not prime or run without the bypass though. I have checked all relays and fuses and everything is good. There is power getting to the ECU as well. I did have 200 ohms resistance on the main grounds which doesnt seem right. I replaced the grounds coming off of the battery and the comp is getting ground. I already changed the crank position sensor and the ASD relay is in proper working condition. The coil is also good.

The final issue is that I cannot connect either of my 2 OBDII scanners to the ECU. I get a link error. The check engine light does come on for a second and then shut off when keys is turned to on position. Everything else on the vehicle is fully functional except for the gauges.

Any tips or help would be greatly appreciated. I am leaning towards new ECU however wanted to get some opinions from you guys. Thank you so much for any help.

Dustin

 

If neither of your scanners will talk to the computer... its a good bet its toast. Have you used the scanners on the truck before? If not.... find another 98 to plug into, and make sure the scanners WILL communicate. If so... more than likely bad ecu.

 

I used the scanners on my neighbors Dakota of the same year and they worked perfect. That is what makes me think its the ecu.

Is there any way besides borrowing someone elses to test the ecu?

 

Not that I am aware of. Sounds to me though, that your scanner works fine, and the ECU.... does not......

 

i would also guess its the computer

 

do u have any pressure in the fuel rails, can you hear the pump launch when you turn it on?

is the ECU fusable links burnt out in the distribution center?

 

I do not get pressure when key is turned on unless I bypass the fuel relay. It seems as though the asd relay is shutting down however that relay is good as is the fuel relay. I do get pressure at the rail when I bypass the fuel relay to the pump.

Where are there fusable links at? I was unaware there were fusable links. Are you referring to fuses/relays? Thanks

 

the fusable links look like big square fuses (.5" square and shaped like a molar) and are in the box on the fender with the relays. they can look good but be failed. find the one that powers the systems your interested in and swap it for a "optional" one like towing, and see if it changes behavior.

 

I have checked all of those and they are good. Each fuse was removed and a continuity test showed connection through the fuse. Which fuse/fuses would be the main ones to really focus on? I also have something that is drawing the battery down. The new battery when left overnight is almost dead. I am assuming that whatever the issue is with no fuel or spark may also be drawing on the battery.

Any other ideas guys or diagnostic tips? I appreciate the help.

 

BUMP Any one have any diagnostic ideas? The battery goes dead after a day sitting (good battery) and still no spark or fuel after all relays and fuses have been checked. Thanks